Cutting tool and method of assembling the cutting tool

ABSTRACT

A cutting tool assembly includes a tool body having a major flare diameter portion disposed adjacent the cutting end of the cutting tool and a puller groove disposed below the major flare diameter portion. A compressible sleeve is disposed about a shank portion of the cutting tool, which is mounted in a tool holder. A washer is fitted about the compressible sleeve, and acts as one of the sides of the puller groove. The location of the puller groove below the major flare diameter portion allows for the cutting tool to be made by cold forming, or the like.

FIELD OF THE INVENTION

The present invention generally relates to a cutting tool and method ofassembly the cutting tool. More particularly, the present inventionpertains to cutting tool and method of assembling the cutting tool in acutting tool holder.

BACKGROUND DISCUSSION

Tool assemblies used to cut hard surfaces, such as rock and asphalt,typically include a rotating wheel or drum with a plurality of cuttingtools mounted around circumference of the wheel or drum. Each cuttingtool is rotatably mounted within a cylindrical bore of the rotatingdrum. However, the material cut by such tools is so abrasive that thecutting tools become worn in just one day's use, and frequently need tobe replaced. Therefore, replacement of such tools must be relativelyeasy to accomplish.

Each cutting tool typically includes a tapered forward cutting end witha carbide tip, and a major flare diameter portion spaced from thecarbide tip. Disposed between the carbide tip and the major flarediameter portion is a puller groove. The puller groove is used forextracting the tool from the holder via an extractor tool. When there isnot sufficient access to the rear of the tool to punch them out, this isthe most desirable method. This groove is typically machined in thecutting tool, which is very costly. In addition, because the groove ismachined close to the tip of the cutting tool, it is susceptible towear.

The cutting tool also includes a shank at its rearward end. Acompressible sleeve is disposed about the shank to fit the tool withinthe bore of the tool holder. A washer may be used to help compress thesleeve when it is assembled into the tool holder. When assembled, themajor flare diameter portion of the cutting tool is disposed adjacentthe washer.

In use, the cutting tool rotates within the compressible spring sleeve.As such, the major flare diameter portion rubs against the washer.Because the largest portion of the cutting tool is disposed adjacent thewasher, the surface contact is maximized causing excess friction betweenthe washer and the cutting tool.

Accordingly, there is a need in the art for a cutting tool with minimalsurface contact between the washer and the cutting tool. In addition,there is a need in the art for a cutting tool body that can be made byforging.

SUMMARY

One aspect of the present invention pertains to a cutting tool forinsertion into a tool holder. A tool body includes a first end forreceiving a cutting tip and a second end for mounting in the toolholder. The tool body includes a tapered forward cutting end. A majorflare diameter portion is disposed adjacent the forward cutting end. Thereduced diameter portion is disposed adjacent the major flare diameterportion. A shank is disposed adjacent the reduced diameter portion. Acompressible sleeve is disposed about the shank. A washer is disposedadjacent to the reduced diameter portion when the cutting tool isretained within the tool holder.

Another aspect of the present invention pertains to a method ofassembling a cutting tool. A cutting tool is provided having a tool bodywith a first end for receiving a cutting tool and a second end formounting in a tool holder. The tool body includes a tapered forwardcutting end, a major flare diameter portion disposed adjacent theforward cutting end, a reduced diameter portion disposed adjacent themajor flare diameter portion, and a shank disposed adjacent the reduceddiameter portion. A compressible sleeve is fitted about the shank of thecutting tool. A washer is fitted about the cutting tool.

Another aspect of the present invention pertains to a cutting tool andholder. A tool body includes a first end for receiving a cutting tip anda second end mounted in a tool holder. The tool body includes a taperedforward cutting end. The cutting tip is disposed in the first end of thetool body. A major flare diameter portion is disposed adjacent theforward cutting end. The reduced diameter portion is disposed adjacentthe major flare diameter portion. A shank is disposed adjacent thereduced diameter portion. A compressible sleeve is disposed about theshank. A washer is disposed adjacent to the reduced diameter portionwhen the cutting tool is retained within the tool holder.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The accompanying drawings provide visual representations which will beused to more fully describe the representative embodiments disclosedherein and can be used by those skilled in the art to better understandthem and their inherent advantages. In these drawings, like referencenumerals identify corresponding elements.

FIG. 1 illustrates a side elevational view, partly in cross section ofan exemplary cutting tool of the present invention and a holder.

FIG. 2 illustrates a side elevational view of an exemplary cutting toolof the present invention.

FIG. 3 illustrates a side elevational view of an exemplary cutting toolaccording to the prior art.

FIG. 4 illustrates a side elevational view an exemplary tool body of thepresent invention.

FIG. 5 illustrates a side elevational view of an exemplary compressiblesleeve according to the present invention.

FIG. 5A is a cross-sectional view of the compressible sleeve of FIG. 5taken along line 5A-5A.

FIG. 6 illustrates a top plan view of an exemplary washer according tothe present invention.

FIG. 6A is a cross-sectional view of the washer of FIG. 6 taken alongline 6A-6A.

FIG. 7 illustrates a side elevational view of a standard extractor tool.

FIG. 8 illustrates a side elevational view of the cutting tool of thepresent invention with the washer disposed midway along the compressiblesleeve.

FIG. 9 illustrates a side elevational view of the cutting tool of thepresent invention with the washer disposed adjacent the reduced diameterportion.

DETAILED DESCRIPTION

FIGS. 1 and 2 show an exemplary embodiment of cutting tool assembly 10and cutting tool 12 of the present invention. While the cutting toolassembly 10 is generally described as suitable for use as road millingtools, it should be understood that the cutting tool assembly 10according to the present invention is applicable to cutting tools otherthan road milling tools. For example, mining and trenching tools.

Cutting tool assembly 10 includes a cutting tool 12 mounted within atool holder 14. When used as a road milling tool, a plurality of cuttingtools are mounted around the circumference of a drum, and are rotatablearound a longitudinal axis to thereby cut a hard surface (not shown).The structure of such a tool is well known in the art, and shown forexample, in U.S. Pat. No. 6,113,195 and U.S. Pat. No. 6,481,803, thedescriptions of which are incorporated herein by reference.

The cutting tool 12 includes a tool body 16 having a first end 18 forreceiving a cutting tip 20. Preferably, the cutting tip 20 is a tungstencarbide cutting tip. However, it should be understood that cutting tip20 can be made of any hard material, depending on application and designpreference. The tool body 16 includes a tapered forward cutting end 22and a major flare diameter portion 24 adjacent the forward cutting end22. A reduced diameter portion or puller groove 26 is disposed adjacentthe major flare diameter portion 24, and is sized to receive the jaws ofa standard extractor tool (see FIG. 7), which will be described in moredetail below.

The cutting tool 12 includes a second end 28 for mounting the cuttingtool 12 in the tool holder 14. The second end 28 of the cutting tool 12includes a shank portion 30 to be received within a bore 32 of the toolholder 14. Disposed about the shank portion 30 is a compressible sleeve34, preferably made from spring steel. The sleeve 34 is spring-loaded toradially expand the sleeve against the inner surface of the bore 32 ofthe tool holder 14.

A washer 36 is disposed about the compressible sleeve 34 and acts tocompress the sleeve 34 so that the cutting tool 12 can be mounted in thetool holder 14, which will be described in more detail below.Preferably, the cutting tool 12 rotates within the bore 32 of the toolholder 14, but is retained therein. Rotation of the cutting tool 12within the bore 32 allows the cutting tool 12 to wear symmetrically,which increases the life of the cutting tool 12.

With reference to FIGS. 2 and 3, the cutting tool 12 of the presentinvention is compared to the cutting tool 40 of the prior art. Withreference in particular to FIG. 3, the cutting tool 40 of the prior artincludes a tapered forward cutting end 42 which receives a cutting tip44 at its end. A reduced diameter portion 46 is disposed between thetapered forward cutting end 42 and a major flare diameter portion 48,and is sized to receive the jaws of a standard extractor tool 49 (seeFIG. 7). A compressible retainer sleeve 50 is disposed about a shankportion 52 of the cutting tool 40 to thereby retain the cutting tool 40within a tool holder (see, e.g., FIG. 1). A washer 54 is disposed aboutthe compressible sleeve 50, which pre-compresses the retainer sleeve 54to facilitate mounting and retaining the cutting tool 40 within the toolholder.

In accordance with the cutting tool 40 of the prior art, the reduceddiameter portion 46 must be machined, because it is not possible toproduce such a grooved portion by cold forming. In particular, thegrooved portion does not allow for the cutting tool to be punched out ofa die when cold forming. However, machining is very expensive, and is tobe avoided. In addition, the surface contact between the major flarediameter portion 48 and the washer 54 is quite large, thereby increasingfriction and negatively affecting rotation of the cutting tool 40 withinthe tool holder, causing premature wear. Moreover, the reduced diameterportion or puller groove 46 is located relatively close to the cuttingtip 44, which causes the top surface of the groove to be worn away,rendering it useless for the puller to extract the tool.

In contrast, the cutting tool 12 of the present invention includes majorflare diameter portion 24 above the reduced diameter portion or pullergroove 26. As such, the washer 36 acts as a bottom surface 36A of thepuller groove 26 and the major diameter portion 24 acts as a top surface24A of the puller groove 26. In addition, as shown in FIG. 2, frictionbetween the top surface of the puller groove 26 and major diameterportion 24 and the cutting tool 12 is minimized because the surfacecontact therebetween is significantly decreased. In operation, the majorflare diameter portion 24 acts as one side of the puller groove 26, andis farther removed from the cutting tip 20, thereby reducing wear of thetop surface 24A and major flare diameter portion 24.

With reference to FIG. 4, the cutting tool 12 of the present inventionwill be described in further detail. In particular, the cutting tool 12includes a tool body 16 having a first end 18 and a second end 28. Thefirst end 18 includes the seat 56 for receiving a cutting tip therein(not shown). The first end 18 includes a tapered forward cutting portion22 adjacent a major flare diameter portion 24. A reduced diameterportion or puller groove 26 is disposed below the major flare diameterportion 24. A shoulder bridging the reduced diameter portion 26 andmajor flare diameter portion 24 constitutes the top surface 24A forengagement of the extractor tool 49. Preferably, the reduced diameterportion 26 is cylindrical. However, it should be understood that thereduced diameter portion 26 may take other shapes depending onapplication and design preference.

The tool body 16 also includes a shank portion 30 for mounting within atool holder 14 (see FIG. 1). Disposed adjacent the shank portion 30 is astepped portion 60. Preferably, a diameter of the stepped portion 60 isgreater than a diameter of the shank portion 30 but is less than adiameter of the reduced diameter portion 26. The stepped portion 60provides surface against which the compressible sleeve is retained whenthe compressible sleeve is mounted about the cutting tool 12.

Because the major flare diameter portion 24 is disposed above the pullergroove, tool body 16 may be formed by cold forming in which a metalblank is formed into a desired shape, thereby avoiding the significantcosts of machining. In particular, a blank is inserted into the diewhich defines the outer surface of the cutting tool, after which theblank is punched to conform it to the shape of the die. However, itshould be understood that tool body 16 may be made in other ways knownin the art, and is not restricted to cold forming.

With reference to FIGS. 5, 5A, 6, and 6A, the compressible sleeve 34 andwasher 36 of the present invention are similar to the compressiblesleeve and washer of the prior art. With reference specifically to FIGS.5 and 5A, the compressible sleeve 34 is preferably made from a springsteel and includes an opening 70, which permits the sleeve to becompressed by the washer 36. With reference to FIGS. 6 and 6A, washer 36includes a bevel 72 that tapers downwardly at an angle, which minimizesthe contact between the washer 36 and the reduced diameter portion orpuller groove 26 of the cutting tool 12. The structure of such a washeris shown, for example, in U.S. Pat. No. 6,113,195, the description ofwhich is incorporated herein by reference. Preferably, this angle isapproximately 45 degrees, but may be greater or smaller, depending onapplication and design preference. The sleeve 34 also includes aplurality of detents 74 (see FIGS. 5 and 5A) which engage a groove 76(see FIG. 4) disposed on the shank portion 30 of the cutting tool 12, tothereby retain the sleeve 34 on the cutting tool 12.

With reference to FIGS. 8 and 9, a method of assembling the cutting tool12 of the present invention within a tool holder 14 includes fitting thecompressible sleeve 34 about the shank portion 30 of the cutting tool 12so that the sleeve 34 is disposed adjacent the stepped portion 60 of thecutting tool 12. A washer 36 is fitted about the second end 28 of thetool body 16 over the compressible sleeve 34 until the washer 36 isdisposed about midway along the compressible sleeve 34.

Once the washer 36 is fitted about the compressible sleeve 34 aboutmidway thereon, the second end 28 of the cutting tool 12 is insertedinto a bore of a tool holder until a first end 80 of the washer 36 abutsthe top surface of the tool holder (not shown). Force is then applied tothe first end 18 and cutting tip 20 of the cutting tool 12 until thesecond end 82 of the washer 36 abuts against the reduced diameterportion or puller groove 26, as shown in FIG. 9. The washer 36pre-compresses the compressible sleeve 34 along its length, to therebyfacilitate insertion of the cutting tool within the bore of the toolholder, as shown in FIG. 1.

In the cutting tool 12 of the present application, the surface contactbetween the cutting tool 12 and the washer 36 is less than the surfacecontact between the washer 36 and the tool holder 14. As such, thewasher 36 will not move, or turn on the holder, but rather remainsstationary with the top surface of the holder. This will reduce the wearon the interface of the holder and the washer. The increased surfacearea between the washer and the holder will prevent the washer fromrotating, thereby reducing the wear on the top of the holder. As such,the tool will require changing long before the interface of the tool andthe washer is worn away and there is a catastrophic failure at theinterface. When the cutting tool is replaced, the washer is replaced aswell.

The presently disclosed embodiments are considered in all respects to beillustrative and not restrictive. The scope is indicated by the appendedclaims, rather than the foregoing description, and all changes that comewithin the meaning and range of equivalents thereof are intended to beembraced.

1. A cutting tool for insertion into a tool holder, comprising: a toolbody having a first end for receiving a cutting tip and a second end formounting in the tool holder, the tool body including a tapered forwardcutting end; a major flare diameter portion disposed adjacent theforward cutting end; a reduced diameter portion disposed adjacent themajor flare diameter portion; a shank disposed adjacent the reduceddiameter portion; a compressible sleeve disposed about the shank; and awasher disposed adjacent to the reduced diameter portion when thecutting tool is retained within the tool holder.
 2. The cutting tool ofclaim 1, wherein the reduced diameter portion is sized to receive astandard extractor tool.
 3. The cutting tool of claim 1, wherein thereduced diameter portion is cylindrical.
 4. The cutting tool of claim 1,wherein the reduced diameter portion is formed by forging.
 5. Thecutting tool of claim 1, wherein the washer includes a bevel that tapersaway from a surface adjacent the reduced diameter portion therebyminimizing contact between the washer and the reduced diameter portion.6. The cutting tool of claim 5, wherein the bevel of the washer is about45 degrees.
 7. The cutting tool of claim 1, further comprising a steppedportion adjacent the shank and the reduced diameter portion, wherein adiameter of the stepped portion is greater than a diameter of the shankand the diameter of the stepped portion is less than a diameter of thereduced diameter portion.
 8. A method of assembling a cutting toolassembly, comprising the steps of: providing a cutting tool having atool body having a first end for receiving a cutting tip and a secondend for mounting in a tool holder, the tool body including a taperedforward cutting end, a major flare diameter portion disposed adjacentthe forward cutting end, a reduced diameter portion disposed adjacentthe major flare diameter portion, and a shank disposed adjacent thereduced diameter portion; fitting a compressible sleeve about the shankof the cutting tool; and providing a washer about the cutting tool. 9.The method of claim 8, wherein the cutting tool is cold formed.
 10. Themethod of claim 8, wherein the washer is disposed on the compressiblesleeve approximately midway along the compressible sleeve.
 11. Themethod of claim 10, further comprising the step of: inserting the secondend of the cutting tool into a bore of a tool holder until a first endof the washer abuts a front face of the tool holder; and applying forceto the first end of the cutting tool until a second end of the washerabuts against the reduced diameter portion.
 12. The method of claim 11,wherein the washer tapers away from the reduced diameter portion at anangle of approximately 45 degrees from a longitudinal axis of thecutting tool.
 13. The method of claim 8, wherein the cutting tool isremoved by grasping the reduced diameter portion of the cutting toolwith jaws of an extractor tool.
 14. A cutting tool and holder,comprising: a tool body having a first end for receiving a cutting tipand a second end mounted in a tool holder, the tool body including atapered forward cutting end; a cutting tip disposed in the first end ofthe tool body; a major flare diameter portion disposed adjacent theforward cutting end; a reduced diameter portion disposed adjacent themajor flare diameter portion; a shank disposed adjacent the reduceddiameter portion; a compressible sleeve disposed about the shank; and awasher disposed adjacent to the reduced diameter portion when thecutting tool is retained within the tool holder.
 15. The cutting tooland holder of claim 14, wherein the reduced diameter portion is sized toreceive a standard extractor tool.
 16. The cutting tool and holder ofclaim 14, wherein the reduced diameter portion is cylindrical.
 17. Thecutting tool and holder of claim 14, wherein the reduced diameterportion is formed by forging or other means.
 18. The cutting tool andholder of claim 14, wherein the washer includes a bevel that tapers awayfrom a surface adjacent the reduced diameter portion thereby minimizingcontact between the washer and the reduced diameter portion.
 19. Thecutting tool and holder of claim 18, wherein the bevel of the washer isabout 45 degrees.
 20. The cutting tool and holder of claim 14, furthercomprising a stepped portion adjacent the shank and the reduced diameterportion, wherein a diameter of the stepped portion is greater than adiameter of the shank and the diameter of the stepped portion is lessthan a diameter of the reduced diameter portion, the washer beingdisposed about the stepped portion when retained in the tool holder.